There's always been a lot of speculation on what this song is really about. Even if you listen to some of Sheryl's interviews on that exact topic, you don't always get the same response.

In my opinion this song ( especially in its original music video version) is an angry response to all the massive publicity she got after her first album become so popular and successful. Some people in the media implied that her good looks and sexual manner ("skanky"?) in performances and some of the early videos were representative of her actual personality. In my opinion, that's simply her on-stage personna, and in real life she is quite different.

So, in response to all the early media attention, the original "If It Makes You Happy" music video showed her sexual side pushed to the absolute maximum, almost in defiance of the media representations. You also get a sense of her anger while watching that video. I consider her being in a glass cage to represent all the media attention, and that her every move was being watched after the success of that first album.

This version here is more mature, more sophisticated, and I think is a much more accurate reflection of the person she really is. And ironically, this version shows how truly beautiful she really is - without a sexy outfit, stage make-up, nor any of the other techniques used by a lot of other performers to make themselves seem sexy.